I've made it. thank you very much. Unfortunatelly servers works very, very slow. I wonder if it's caused by raid (raid 1). Do you think that it is better idea to buy a raid controller or this one on motherboard is fine?

I did and it helped me with NIC but the server is still slow. I think it's because of embedded raid. what is its quality? do you think an external raid controller should be consider? Or maybe raid 10 would be a good idea?

Yes RAID 10 could be faster than RAID 1, but you may want to find the real bottleneck first. Also, make sure you use HDDs from the Tested memory and hardware list. Also, SATA drives could be very sensitive to vibration.